[agrahamcampbell]

I just picked up my first DSLR, a K-500, a couple of months ago, and so far am having a great time. Like any good Pentax noob, I picked up a number of cheap old lenses in the first couple of weeks. Mostly a couple of Pentax-M primes, which have been fun, but I've developed somewhat of a love-hate relationship with the long zoom I picked up, a Tamron 75-300mm f/4-5.6 LD.

I have a ton of fun with the long focal length - I mostly use it for wildlife shots and for a bit of people-watching (at the beach, etc.). It's an OK lens overall and I've actually taken some pretty decent shots with it, but in bright light I seem to pick up some CRAZY AGGRESSIVE purple fringing - enough that I really can't get it out effectively in PP (though I am still a bit new to working with RAW files), and enough that it kind of ruins the image. This seems to be especially prevalent at the 300mm end of the range.

I guess the question is, is this the lens or is it me? I feel like I've heard some complaints about Tamron long zooms and CA, though I'm perfectly willing to believe it's a problem with my technique.

I've been mostly shooting with apertures around f/8-11, and I've been using a UV filter but so far no hood. I don't have a ton of money to pick up a new lens at this point, but I have had my eye on the Pentax DA L 55-300mm based on the reviews I've read. Is that lens considered much better than the Tamron (or to similarly priced/spec'ed Tamrons), or am I looking at relatively minor differences until I move significantly further up the quality/price chain? (Also open to other suggestions, zoom or prime...)

I'd rather not throw money at the problem for minimal gain in lieu of honing my skills and saving up for something better, but also not looking to bang my head against the wall with an inferior lens for months on end.

Thanks in advance for the advice!

[vonBaloney]

It is the lens, not you. You may get somewhat better results by removing the UV filter, especially if it is a lousy filter. (Even if it is a good filter, there no particular reason to use it unless you're getting salt spray at the beach or something.) Adding a hood may also help marginally. The Pentax is still a consumer zoom and can't compare IQ-wise to the high-end lenses, but nevertheless should be worlds better in the crazy aggressive purple fringing department...

[mythguy9]

I agree, sometimes people blame their lenses because they are bad, but sometimes lens are really subquality, so don't stress to much.

Try not to use both ends of your zoom, stick to, let's say 100-250, because many lenses perform worst at their extreme ends.

I recently bought a prime Soligor 200mm f3.5 with $25 and am quite happy with it. I can't recommend any auto lens but yes the WR 55-300 seems like a good choice. I mean if you don't mind primes, then spend about $100 to pick up 2-3 primes that covers the 70-300 range, because old primes are generally better bang for the bucks, except you lose auto focus and zoom.

[Sorver]

I have had the same issue with my Sigma 70-300 bought second hand on eBay 😀but only when shooting directly into the suns direction and it has a filter that I am going to remove now, otherwise the dreaded purple fringing hasn't worried me too much but am considering 55-300wr and a wide angle prime for my travels.

[agrahamcampbell]

Thanks, all! That's really helpful information.

Yeah, good to know it's not something I'm doing (or maybe not, since that eventually means more $$$ if I want to shoot at 300mm ). I don't think the filter makes a ton of impact, since I've shot with it on and off with no real difference (I mostly just use it to protect the lens anyway).

Interesting thought regarding the Soligor prime - I hadn't looked too far beyond Asahi Pentax for the older primes, but good to hear that some of the third parties have decent products as well. Though, then again, the 200-300mm range is where I probably see myself most relying on autofocus and automatic metering (especially automatic metering...) due to the fact that it's a bit harder to catch moving things at that range!

I'll think a bit more on the DA or DA-L 55-300... I have some travel coming up in the next month and will probably do a fair amount of shooting in that range. Any thoughts on what the next step up would look like? Is there anything significantly better that I could look into in, say, the under $400 range used, or am I looking way beyond that? (Gauging whether there is anything I could justify grabbing for myself in the next year...)


Thanks again to all for the help!

[boriscleto]

I'll think a bit more on the DA or DA-L 55-300... I have some travel coming up in the next month and will probably do a fair amount of shooting in that range. Any thoughts on what the next step up would look like? Is there anything significantly better that I could look into in, say, the under $400 range used, or am I looking way beyond that? (Gauging whether there is anything I could justify grabbing for myself in the next year...)

Under $400 you might find the manual focus version of the Sigma APO 400/5.6. The Sigma came in APO and non-APO versions, only the APO is worth getting. The Pentax A 400/5.6 is usually over $500. The FA* 400/5.6 is ~$1000.

The DA L 55-300 is a fine lens for its price. You won't find anything better for less than $700 - $800.

[normhead]

Under $400 you might find the manual focus version of the Sigma APO 400/5.6. The Sigma came in APO and non-APO versions, only the APO is worth getting. The Pentax A 400/5.6 is usually over $500. The FA* 400/5.6 is ~$1000.

The DA L 55-300 is a fine lens for its price. You won't find anything better for less than $700 - $800.

I'm not sure why this isn't the lens of choice for everyone in your situation. Purple fringing is real and it's more of an issue on old glass than new glass. The 55-300 was designed a bit oddly for a long lens in that it's really strong in the long end, something most cheaper telephotos aren't. That makes it your number one choice if you're looking for 300 at a bargain price. You can do a lot of research and evaluate a lot of lenses and end up with the DA 55-300 as your final choice. Or you can save a lot of time, and probably some grief, and just go for it.

If 300 and inexpensive are your two most important criteria, there's simply nothing as good as the DA 55-300. I don't own one, but many times I've been tempted to clear out my cheaper 300mm lenses and get one. Where I live selling old lenses is such a pain in the behind, but someday.

[snostorm]

Hi agrahamcampbell,

The "easy" way to attack PF problems is to buy better lenses, but the problem does not disappear, even with the best glass available -- believe me, I know. . . I've now got 9 lenses that cover 300mm, including the FA* 300/4.5, FA* 300/2.8, Sigma EX100-300/4, Sigma EX 300/2.8 APO, Tamron SP 300/2.8 Adaptall 2,and a Canon FD 300/4 L (converted to K mount), and they will all show PF under certain conditions -- maybe not as badly as the Tamron 70-300, but it's there.

The most common cure is to correct this in PP by desaturating the magenta channel, choosing the correct hue, but that's problematic because this causes the fringing to turn gray, and the range of hues in PF is pretty wide, so one ends up desaturating too many hues that rightfully belong in the image. So much for the one click cure. . .

Since I know that PF will show up, even with the best ultra tele lenses available to me, I've chosen to develop a different PP strategy to deal with the problem. It's time intensive, and this makes it practical only for images that I feel are good enough to deserve the time, which are relatively few and far between. You need a good image editor with a clone tool that allows cloning in different modes, in this case "color", and you need to be able to control the opacity of the clone as well as the hardness of the edges of the tool. I use Corel PSPPX6 for this, and I know that PS and Essentials at least have these clone modes. If you really want to restore the correct colors to every pixel on the image, this can be very exacting work, but usually my goal is pretty much to just take the "electricity" out of the fringing so it's not too distracting from the main subject, and this can usually be done relatively quickly and easily. I won't go into all of the techniques I've discovered over time, but in the very common case of bare tree branches silhouetted against a bright sky, you can use a pretty large brush, @ 30% opacity, 0 hardness, and just use the color of the sky as the source with the source not aligned to the target so you easily can go back to the same source area with the same color with each click, no matter where the target is on the image. With this technique, there is no image that I can't save from PF, or CA for that matter, if it's worth the trouble.

Getting lenses where color aberrations are well corrected with very low dispersion elements is usually an expensive proposition, and the extent of the expense is usually at least directly proportional to the FL. Although it's fun to collect great lenses, it's very empowering to find solutions that don't involve spending a ton of money if budget is a concern.

The DA 55-300 in all variations corrects for color aberrations very well with their ED elements, so it's always an alternative, but even some of the premium older ultra tele primes for Pentax don't really correct for color aberrations that well, the K/M*/A* 300 f4s and the Tamron SP 300/2.8 model 60B are all examples of this, IMO.

Scott

[Just1MoreDave]

...I'll think a bit more on the DA or DA-L 55-300... I have some travel coming up in the next month and will probably do a fair amount of shooting in that range. Any thoughts on what the next step up would look like? Is there anything significantly better that I could look into in, say, the under $400 range used, or am I looking way beyond that? (Gauging whether there is anything I could justify grabbing for myself in the next year...)

I have the SMC Pentax 300mm f4, Tokina SD 400mm f5.6 and Tamron 500mm f8 mirror.

The mirror lens is good for a mirror lens but a lot of the time, too limited in some way - f8 or the unusual bokeh. At the going price for a good one today, I would skip it. The <$100 ones are really not worth it.

The Pentax is better than the inexpensive zooms that go up to 300mm, but I never compared it to the DA 55-300. Its main problem is size: over 1000 grams, 77mm filter. Second, it has typical fringing in out of focus areas, the type that is green in the foreground and purpleish in the back. This is common in the K series, lenses weren't corrected for it. I think the Takumar 300mm f4s share the formula. The fringing is not an issue for me, the size sometimes is. These may be worth a look.

I use the Tokina a lot because it's almost the same size and weight as the K300/4, but 400mm. Often when 300 is good, 400 is better. It has a KA mount, manual focus. The Tokina has a different purple fringing like the cheap zooms, which Lightroom handles pretty well. It is internal focus, has a slideout hood and a tripod mount. It's a pretty good lens for me. There is an RMC version that is not as good and an AT-X version with autofocus that is optically better.

I find the 400mm length a good compromise between size, weight and cost. I know Sigma made lenses similar to the Tokina ones. The Pentax-A 400mm f5.6 is still reasonably priced but probably over $400.

[normhead]

I've now got 9 lenses that cover 300mm, including the FA* 300/4.5, FA* 300/2.8, Sigma EX100-300/4, Sigma EX 300/2.8 APO, Tamron SP 300/2.8 Adaptall 2,and a Canon FD 300/4 L, and they will all show PF under certain conditions -- maybe not as badly as the Tamron 70-300, but it's there.

You are the 300mm lens god, we are not worthy.

[snostorm]

I'm not sure why this isn't the lens of choice for everyone in your situation. Purple fringing is real and it's more of an issue on old glass than new glass. The 55-300 was designed a bit oddly for a long lens in that it's really strong in the long end, something most cheaper telephotos aren't. That makes it your number one choice if you're looking for 300 at a bargain price. You can do a lot of research and evaluate a lot of lenses and end up with the DA 55-300 as your final choice. Or you can save a lot of time, and probably some grief, and just go for it.

If 300 and inexpensive are your two most important criteria, there's simply nothing as good as the DA 55-300. I don't own one, but many times I've been tempted to clear out my cheaper 300mm lenses and get one. Where I live selling old lenses is such a pain in the behind, but someday.

BTW, I agree with Norm here. With all of the premium 300mm primes that I have, I still bought a DA55-300 over a year ago for a lightweight quality 300mm alternative, and have recently purchased an HD WR version to have a lightweight WR 300 to go with my WR bodies. I now use the standard DA 55-300 with my Q bodies exclusively for a very good extreme reach super tele, and the HD WR often gets the call when I'm just wandering around looking for good places to find the birds I like to shoot.

Scott

[jimr-pdx]

Reading here I've found three other random-luck choices for great prices. The Pentax FA 80-320 has some fans but most find it indifferent, so for a sub-$120 choice it can be a winner... some times. The non-power-zoom FA 100-300 is similar and more people seem to like it; pkf reviews here!

I've had good images with Quantaray/Sigma 100-300mm f/4.5-6.7, but it needs more light than the 55-300 at the long end. I've had copies of the 100-300 that showed low contrast, the images felt soft but a contrast boost showed it to be pretty sharp. These can be had cheaply (mine was ~$30!) and by using a tripod in weaker light it can do pretty well. It's also a ff/film lens so it vignettes less than the DA zoom.

Overall though, the 55-300 is consistently excellent with a more versatile range and decent speed. You won't go wrong with a copy of it!

[Na Horuk]

Some great replies already. You chose right by shooting raw. That way you can use lens profiles and remove a lot of lateral CA, add sharpness an contrast, saturation or even change the hues. The other steps that might improve IQ is using a lens hood.
If your photos aren't sharp, try doing a test where the camera is immobile and using 2 sec timer (or remote release) in natural light with low ISO. This will let you diagnose how sharp the lens can be.
Purple fringing is a general problem in digital cameras and nothing much can be done. Many raw developing software have an automatic option to "defringe" but its never 100%. Just keep in mind that PF isn't as terrible as it appears to the photographer. Other viewers probably won't even notice it. Its one of those things that drives you crazy in your own photos. I remember reading that using a very strong UV filter can help reduce purple fringing, but haven't seen any tests that would prove this theory. And UV filters might introduce their own problems, so only use one if its high end.
All that being said, 300mm and high quality.. well, that will cost. The DA 55-300mm is often pointed to as the best bang per buck for 300mm. The new version with HD coatings (as opposed to the older one with SMC) might be even better. Plus, its WR, which is something that most other brands won't offer. And it has Quickshift. So it will give you a taste of premium features

[agrahamcampbell]

Definitely some great responses here - thanks everyone! The PentaxForums community definitely does not disappoint!

Sounds like there is a lot of love for the Pentax DA-L/DA/HD WR 55-300mm zoom as a sub-$700 option, so I probably will grab a copy of one of those. Might just go for the DA L version for now, since it's cheap and, given how it's re-selling, I can always pawn it off in a few months if I decide to upgrade

Thanks especially to Scott/snostorm for the PP suggestions! I had mostly been just using the raw processor's chromatic aberration correction, with modest success, though I had also tried de-saturating spots and doing plain-old 'regular' cloning. The latter two are pretty labor intensive and require constant checking to make sure I'm not creating patterns or spots that don't match the rest of the image... sounds like using the "color" mode allows for a wider brush and a bit quicker work.

Just keep in mind that PF isn't as terrible as it appears to the photographer. Other viewers probably won't even notice it. Its one of those things that drives you crazy in your own photos.

Gooooood point!

[vonBaloney]

The last few versions of Lightroom have de-fringing controls for zapping the purple and green varieties -- can be use a localized brush or global to the image. (It also has a checkbox for automatically correcting lateral CA.)